Platt Hill State Park is an undeveloped public recreation area in Winchester in northwestern Connecticut’s Litchfield County. Covering 159 acres, it is devoted to simple outdoor use such as hiking, picnicking, and enjoying views across the surrounding landscape rather than built attractions. The park was one of several recreation areas acquired in the 1950s with funds bequeathed by George Dudley Seymour. It first appeared on state rolls in the 1960 edition of the Connecticut State Register and Manual, then listed at 50 acres, indicating that its recorded size later changed. Its importance rests on preserving hilltop open land for public access and scenic outlooks.